What is bipolar disorder?

Bipolar disorder is a serious mental illness that is characterized by depressive and manic episodes. Advanced neurobiological research and assessment techniques have shown this disorder to have biochemical origins and a genetic element. Research indicates that stress may play a role in the precipitating recurrence of episodes. The main treatment interventions include lithium, mood-stabilizing anticonvulsants, antipsychotics, and psychotherapy.

Although mood fluctuations are a normal part of life, individuals with bipolar disorder experience extreme mood changes. Bipolar disorder, or bipolar affective disorder (also called manic-depressive disorder), has been identified as a major psychiatric disorder characterized by dramatic mood and behavior changes. These changes, ranging from episodes of high euphoric moods to deep depression, with accompanying behavioral and personality changes, are devastating to those with the disorder and perplexing to the loved ones of...

Introduction

Although mood fluctuations are a normal part of life, individuals with bipolar disorder experience extreme mood changes. Bipolar disorder, or bipolar affective disorder (also called manic-depressive disorder), has been identified as a major psychiatric disorder characterized by dramatic mood and behavior changes. These changes, ranging from episodes of high euphoric moods to deep depression, with accompanying behavioral and personality changes, are devastating to those with the disorder and perplexing to the loved ones of those affected. As of 2015, the Substance Abuse and Mental Health Services Administration reported that approximately 2.6 percent of the US population over the age of eighteen suffers from bipolar disorder. The disorder is divided fairly equally between men and women.

Clinical psychiatry has been effective in providing biochemical intervention in the form of mood stabilizers such as lithium carbonate or valproate, which both stimulate the release of the neurotransmitter glutamate in order to stabilize or modulate the ups and downs of this illness. Lithium treatment is most effective when treating individuals with pure mania, which is characterized by periods of euphoria and depression. Mood-stabilizing anticonvulsant medications, such as oxcarbazepine (Trileptal), carbamazepine (Tegretol), and lamotrigine (Lamictal) are often used to treat bipolar. Atypical antipsychotic medications, antidepressants, electroconvulsive therapy (ECT), and nonmedical therapies such as sleep management and psychotherapy are increasingly utilized to treat individuals with bipolar disorder. Psychotherapy is seen by most practitioners as a necessary adjunct to medication.

Symptoms

In the manic phase of a bipolar episode, individuals may experience inappropriately good moods, or “highs,” or may become extremely irritable. During a manic phase, they may overcommit to work projects and meetings, social activities, and family responsibilities in the belief that they can accomplish anything; this is known as manic grandiosity. At times, psychotic symptoms such as delusions, severe paranoia, and hallucinations may accompany a manic episode. These symptoms may lead to a misdiagnosis of other psychotic disorders such as schizophrenia. Although it may be difficult to arrive at a differential diagnosis between schizophrenia and bipolar disorder when a person is acutely psychotic, a long-term view of the individual’s overall symptoms and functioning can distinguish between the two disorders.

The initial episode of bipolar disorder is typically one of mania or elation, although in some people, a depressive episode may signal the beginning of the disorder. Episodes of bipolar disorder can recur rapidly—within hours or days—or may have a much slower recurrence rate, even of years. The duration of each episode, whether it is depression or mania, varies among individuals but normally remains fairly consistent for each individual.

Types

According to the fifth edition of the
Diagnostic and Statistical Manual of Mental Disorders
(DSM-5, 2013), which is the diagnostic manual of the American Psychiatric Association, there are several types of bipolar disorder. Bipolar disorder specifiers are categorized according to the extent of severity; the types of the symptoms; the changes in activity, energy, and mood; and the duration of the symptoms.

Bipolar I disorder is characterized by alternating periods of mania and depression. At times, severe bipolar disorder may be accompanied by psychotic symptoms such as delusions and hallucinations. For this reason, bipolar I disorder is also considered a psychotic disorder. The prevalence of bipolar I disorder is divided fairly equally between men and women. However, women report more episodes of depression than men and are more likely to be diagnosed with bipolar II disorder.

Bipolar II disorder is characterized by alternating episodes of a milder form of mania (known as hypomania) and depression. In bipolar II disorder, although there is an observable change in mood and functioning, the hypomanic episode causes less severe impairment than that seen in mania. It is very rare for an individual’s diagnosis to change from bipolar II disorder to bipolar I disorder.

Cyclothymia
is a form of bipolar disorder in which hypomania alternates with a low-level, chronic depressive state. Seasonal affective disorder (SAD)
is characterized by alternating mood episodes that vary according to seasonal patterns; the mood changes are thought to be related to changes in the amount of sunlight and accompanying effects on an individual's circadian rhythm and levels of the hormone
melatonin. In the northern hemisphere, the typical pattern is associated with manic symptoms in the spring and summer and depression in the fall and winter. Manic episodes often have a shorter duration than the depressive episodes. Bipolar disorder must be differentiated from depressive disorders, which include major depression (unipolar depression) and dysthymia, a milder but chronic form of depression.

Comorbidity

Clinical comorbidity is the existence of two or more disorders in the same individual. In 2011, the Archives of General Psychiatry (now JAMA Psychiatry) reported on a World Mental Health survey conducted by researchers from Harvard University. The survey found that 75 percent of participants with bipolar spectrum disorder also met the criteria for at least one other psychiatric disorder, with anxiety disorder as the most prevalent co-occurring condition. Less than half of those with bipolar disorder reported receiving mental health treatment for the condition. Other frequently occurring comorbid disorders are attention-deficit hyperactivity disorder (ADHD), personality disorders, and substance use disorder.

Causes

The causes of bipolar disorder are not fully understood. However, family, twin, and adoption studies indicate that genetic factors play a major role. As of 2015, the Depression and Bipolar Support Alliance reports that approximately two-thirds of individuals with bipolar disorder have at least one close relative with the disorder. In fact, it is not uncommon to see families in which several generations are affected by bipolar disorder. Serotonin, norepinephrine, and dopamine, brain chemicals known as neurotransmitters that regulate mood, arousal, and energy, respectively, are thought to be altered in bipolar disorder.

One theory is that bipolar disorder is associated with dysregulation in brain regions that are implicated in emotion such as the amygdala and basal ganglia. This theory is supported by functional brain imaging studies that indicate that during cognitive or emotional tasks, people with bipolar I disorder show different patterns of activity in the amygdala. In terms of structural brain imaging, people with bipolar disorder also display differences in the volume of activity in certain regions such as the amygdala and basal ganglia.

A diathesis-stress model has been proposed for some psychosomatic disorders such as hypertension. This model has also been applied to bipolar disorder. In a diathesis-stress model, there is a susceptibility (the diathesis) for the disorder. An individual who has a diathesis is at risk for the disorder but may not show signs of the disorder unless there is sufficient stress. In this model, a genetic, structural, or biochemical predisposition toward the disorder (the bipolar diathesis) may lie dormant until stress triggers the emergence of the illness. The stress may be psychosocial, biological, neurochemical, or a combination of these factors.

A diathesis-stress model can also account for some of the recurrent episodes of mania in bipolar disorder. Investigators suggest that positive life events, such as the birth of a baby or a job promotion, as well as negative life events, such as divorce or the loss of a job, may trigger the onset of episodes in individuals with bipolar disorder. Stressful life events and the social rhythm disruptions that they cause can have adverse effects on a person’s
circadian rhythms. Circadian rhythms are normal biologic rhythms that govern such functions as sleeping and waking, body temperature, and oxygen consumption. Circadian rhythms affect hormonal levels and have significant effects on both emotional and physical well-being. For those reasons, many clinicians encourage individuals with bipolar disorder to work toward maintaining consistency in their social rhythms.

Investigators have compared the course of bipolar disorder to kindling, a process in which epileptic seizures increase the likelihood of further seizures. According to the kindling hypothesis, triggered mood episodes may leave the individual’s brain in a sustained sensitized state that makes the person more vulnerable to further episodes. After a while, external factors are less necessary for a mood episode to be triggered. Episode sensitization may also account for rapid-cycling states, in which the individual shifts from depression to mania over the course of a few hours or days. Some individuals are diagnosed with a subtype of bipolar disorder known as rapid cycling bipolar disorder, which is defined as four or more episodes per year. Rapid cycling is characterized by poorer outcome.

Impact

The burden of bipolar disorder is considerable. In addition to experiencing functional impairment during illness episodes, many people with bipolar disorder experience ongoing functional impairment between episodes. In 2002, the World Health Organization (WHO) reported that bipolar disorder was responsible for more adjusted life-years than any form of cancer or such major neurologic diseases as Alzheimer's and epilepsy. It was estimated that bipolar disorder was the sixth leading cause of disability worldwide among adults between the ages of fifteen and forty-four. Bipolar disorder is associated with the highest rate of suicide out of all of the psychiatric disorders. In one large-scale study, when asked to rate their perception of their well-being in terms of their culture, values, and how they live in relation to their goals, standards, and expectations (that is, their quality of life), individuals with bipolar disorder rated their quality of life lower than members of the general population did. Indeed, study findings suggest that quality-of-life ratings are poorer in bipolar disorder than they are in anxiety disorders and in depression but are better than compared with quality-of-life ratings in schizophrenia.

Organizations such as the National Alliance on Mental Illness (NAMI) and support groups such as the Depressive and Bipolar Support Alliance (DBSA) have provided a way for people with bipolar disorder to share their pain as well as to triumph over the illness. Many people have found comfort in knowing that others have suffered from the mood shifts, and they can draw strength from one another. Family members and friends can be the strongest supporters and advocates for those who have bipolar disorder or other psychiatric illnesses. Many patients have credited their families’ constant, uncritical support in addition to competent effective treatment including medications and psychotherapy, with helping them cope with the devastating effects of the illness. Early intervention, relapse prevention, and treatment of the disorder are necessary to prevent the possibility of a tragic outcome.

Treatment Approaches

Medications have been developed to aid in correcting the biochemical imbalances thought to be part of bipolar disorder. Lithium carbonate is effective for the majority of individuals who take it. Many brilliant and successful people have reportedly suffered from bipolar disorder and have been able to function successfully with competent and responsible treatment. Some people who have taken lithium for bipolar disorder, however, have complained that it robs them of their energy and creativity. They say that they actually miss the energy associated with manic phases of the illness. This perceived loss, some of it realistic, can be a factor in relapse associated with lithium noncompliance.

Other medications have been developed to help those individuals who are considered lithium nonresponders or who find the side effects of lithium intolerable. Anticonvulsant medications, such as divalproex sodium (Depakote), carbamazepine (Tegretol), and lamotrigine (Lamictal), which have been found to have mood-stabilizing effects, are often prescribed to individuals with bipolar disorder. During the depressive phase of the disorder, electroconvulsive therapy (ECT) and lamotrigine (Lamictal) have also been administered to help restore the individual’s mood to a normal level. Phototherapy is particularly useful for individuals who have SAD. Atypical antipsychotic medications such as risperidone (Risperdal), olanzapine (Zyprexa), and quetiapine (Seroquel) have also been prescribed to individuals with bipolar I disorder for the treatment of mania.

Cognitive behavior therapy is a form of therapy that addresses an individual’s beliefs, assumptions, and behaviors to improve that person’s emotional responses and health. Interpersonal social rhythms therapy encourages individuals to achieve and maintain stable routines, emphasizing the link between regular routines and moods, whereas the interpersonal component of the therapy focuses on the interpersonal issues that arise in individuals’ lives. Psychotherapy, especially cognitive behavior therapy or interpersonal social rhythm therapy, is viewed by most practitioners as a necessary adjunct to medication. Indeed, psychotherapy has been found to assist individuals with bipolar disorder in maintaining medication compliance.

Local mental health associations are able to recommend psychiatric treatment by board-certified psychiatrists and licensed psychologists who specialize in the treatment of mood disorders. Often, temporary hospitalization is necessary for complete diagnostic assessment, initial mood stabilization and intensive treatment, medication adjustment, or monitoring of an individual who feels suicidal.